Hydrogen ligands

Hydrogen cyanide reactions catalysts, 6,296 Hydrogen ligands, 2, 689-711 Hydrogenolysis platinum hydride complexes synthesis, 5, 359 Hydrogen peroxide catalytic oxidation, 6, 332, 334 hydrocarbon oxidation iron catalysts, 6, 379 reduction... 

Figure 9-16 shows the molecular shapes of methane, ammonia, and water, all of which have hydrogen ligands bonded to an inner atom. These molecules have different numbers of ligands, but they all have the same steric number. 

From the Lewis structure, we see that oxygen bonds to three hydrogen ligands and has one lone pair. The sum of the lone pairs and the ligands yields a steric number of 4. 

The synthesis, structure, and catalytic properties of a Pd11 complex with a partially hydrogenated ligand, shown in Figure 31, are described.393 This study provides the first asymmetric epoxidation of alkenes catalyzed by a palladium complex.393... 

Figure 31 A Pd11 complex with a partially hydrogenated ligand acts as a catalyst for asymmetric epoxidation.

Figure 4.16 Double bond (a) Lewis model of two tetrahedra sharing an edge, (b) Domain model the two single electron pair domains of the double bond are pulled in toward each other by the attraction of the two carbon cores forming one four-electron double-bond domain with a prolate ellipsoidal shape, thereby allowing the two hydrogen ligands to move apart.

Scheme 17.6 Transition states for the transfer of a hydrogen atom from a molecular hydrogen ligand to a formate ligand a) four-centered b) four-centered and base-assisted [66] and c) six-centered [59].

The phosphoranes (81),64 (82),65 and (83),68 each containing a hydrogen ligand, have been prepared by the now standard procedure from amino-phosphines and amino-alcohols. A similar reaction of the amino-alcohol (84) gave oxazaphosphol-idine derivatives (85).6 7... 

The first step of the reduction by cobalt(II) chloride and NaBH4 involves the production of cobalt hydride species which is capable of exchanging hydrogen ligands with the medium. The second step is a hydrometallation reaction followed by a reductive cleavage of the carbon-cobalt bond. The hydrocobaltation seems to be reversible, as indicated by deuterium label incorporation93. 

It should be both possible and profitable to divide all reactions of transition-metal hydrides into these three classes. Even concerted reactions, in which the metal interacts with the substrate at the same time as its hydrogen ligand does, can usefully be divided according to which of the above hydrogen transfer reactions they most resemble. 

A The results of estimating the number of the Is hydrogen ligand orbitals that are unaffected by the symmetry operations of the C3v point group are ... 

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